Next Saturday is Earth Day and we’ll see thousands take to the streets in Cleveland, DC and cities across the country in a March for Science. Monday’s The Sound of Ideas, we’ll talk with the heads of major science institutions in Northeast Ohio like the Great Lakes Science Center and the Museum of Natural History about their involvement in the march and why they’re taking a stand. Then, a update on parks in Northeast Ohio. Plus, one local woman's story of discovering slavery letters from her ancestor.